Printer Power usage

I recently bought a kill a watt, to double check my power usage in the printers. Kinda cool to know.

So 6 Mp3DP printers, all running insulated heated beds @ 63C and 218C hot ends. 68-70 degree room for an average 24 hours worth of printing. Came out to 10.3kWh, so for me that is about $2.55 per day in electricity costs. Neat, lower than I thought.

All 6 at rebooted sitting idle consume ~42W, higher than I expected. All heating up bed and nozzle, almost 1000W. During printing it said anywhere from 200-600W, mostly between 250-450W. Much higher than I thought.

Just thought I would share, anyone that sees my “farm” that is the first question asked usually.

It’s that darn heat bed… If you just kept the room at ~65°C you would see that they use much less power.

I just can’t really believe the idle draw of these power supplies. I am going to have to look into wiring up the power off after a print. I also want try and test the thermal insulation effects as well. Some of my beds are on kiln insulation and two are just cork backed. If I only Had one of those fancy thermal cams of Barry’s. For a quick and dirty I will heat two of them up and see if one hold temp substantially longer after power down.

You might also gain some efficiency by using a single larger power supply that powers all of the printers.

How many raspberry pi’s do you have?

I used to use a computer’s CPU to power a printer, and I wired the 5V standby to the ramps, and the control of the PSU was in the firmware. That would do a similar thing (gcode at the beginning to start it up, and at the end to turn it off).

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My pc would overcurrent a 1000va apc ups when I hit render for a picture similar to the tshirt pics I posted the other day. It doesn’t even have that powerful of a video card.

That sucks, I was actually looking at getting a UPS the last few days to try and make it through some of the smaller power outages around here. Kinda the whole reason I bought the killawatt. 1500-1900va 900W model I believe. I was really trying to get a 15 minute buffer. I have had a few outages in the mornings where usually only a printer or two had not finished an 8-10hr print.

Something like, https://amzn.to/2tdUajM, but the time calc for that brand is non-existent.

Oops found it, 200W 35 min, 500W 10 minutes. So I think for me that is a good investment. I should get a good 15minutes out of it. If I am around/awake I can kill all the heated beds to prolong it.

I wonder what the power usage difference would be with/without an enclosure.

Couldn’t you get fancy and power the heated beds separately (from wall power) while the electronics and steppers and extruders are powered from the UPS? Would require engineering your power distribution a bit and figuring out what to do about the heated bed error that could occur due to a difference between commanded bed temperature and actual temperature.

That’s how the gmax/gcreat printers work, because the bed is so huge, but a common thing in the hypercube community is using the wall power for the beds, however, it’s commonly discouraged though.

Stay away from cyberpower upses. They’re junk. Client has about 90 of them in three classrooms under the desks. When the battery dies, usually after a year, the whole unit quits working. Kind of takes the “uninterruptible” out of ups. APC upses will keep working when the battery dies, and the batteries are hot swappable. They cost more, but you get what you’re paying for. Also, UPS run times are a lot like phone run times. Sure it will run a desktop with a 17" monitor for 4 hours, what they don’t tell you is it’s a low power intel nuc with the display’s backlight disabled… :wink:

imho, $0.25 per KW is not a big deal. of course it’s not as here we have $0.06 ($0.12 for business)
so reducing consumption I see just as a technical challenge.

heating entire room to 65C could be even more expensive then just heat beds.
and this solution like a closed box is not an option for PLA - it likes good cooling, otherwise you will get printing defects.

ok, so

  1. small saving of power (not money). in russian 3d printing community it’s popular last time to use 220V heaters for bed, driven by SSR. no unnecessary power transformations, direct heating from outlet. and yes, one powerful power supply could be used for a few printers.

  2. much more saving of power. there are a lot of entry level 3d printers on the market that designed for printing PLA only - do not have heated bed. So may be it’s possible to do not heat it at all? If you have proper coating on the bed. May be one of the best solution is to have changeable metal plate with magnets like a Prusa has.
    https://www.youtube.com/watch?v=dTR5HxVDrU8

  3. next step. Increase effectiveness of printing. Imagine that stepper driver tuned to produce constant current. No matter how it loaded. And with prusa-like printer you just can’t print too fast - bed+detail are relative heavy. But you can increase productivity by using a 3d printer which has as light moving parts as possible. So probably best answer here is delta-robot, may be up to twice faster. Or at least good core-xy.

I used to use a computer’s CPU to power a printer
That's pretty impressive. I didn't even realize they did AC/DC conversion. :P

Thanks, I knew you had some experience with them!

As for saving power it isn’t really a money thing, just interesting too me. As in what works and what doesn’t, can I make a UPS last a few minutes longer with a little insulation.

 

If need to continue printing for a long time after power loss i think an interesting idea is to increase voltage to 14.3V (it’s safe for most boards except pure mega. Only things you should care are fans) and attach an acid accumulator (as example 100Ah) between power supply and the printer.

Or you can tune system to make proper printing pause on power loss (so you may continue on restore).

In both cases cold bed is you best friend.